Hydraulic puller



June 26, 1934. A. M. MclNTosH 1,964,524

HYDRAUL I C `FULLER Filed July 27, 1952 I INVEN TOR. /Q/YDREW M. MCI/v TosH BY Mhz/,W

ATTORNEY Patented June 26, 1934 UNITED STATES PATENT OFFICE 2 Claims.

The invention relates to an hydraulic puller or jack for use in moving wheels, gears, pulleys, sleeves or the like along shafts or spindles which frictionally and/or Wedgedly mount them.

An object of the invention is to provide a puller of the class described which requires a minimum of manipulation and effort on the part of an operator during the application and use thereof.

Another object is to provide a puller which is adapted for use in a maximum number of both usual and unusual Working situations.

A further object of the invention is to provide a puller structure requiring a minimum number of parts in its assembly.

A more speciiic object is to provide a puller 'which is particularly adapted for use in loosening the engagement of a tapered shaft portion in a complementary conical bore of an element which is frictionally and wedgedly mounted on the shaft portion.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth or be apparent in the following description of typical embodiments of the invention, and in the accompanying drawing, in which,

Figure 1 is an external side View of a puller embodying the present invention.

Figure 2 is a transverse section at 2 2 in Figure 1.

Figure 3 is a longitudinal section at 3 3 in Figure 1, the operative elements of the puller being disposed as for releasing a wheel hub, or the like, from a tapered axle end.

Figure 4 is a longitudinal section of another embodiment of the puller, the present embodiment being shown as applied for releasing a different type of wheel hub from its axle.

In the structure of the puller unit 5 of Figures 1 to 3 inclusive, an outer body portion 6 is provided, said body portion being generally tubular and having an enlarged bore portion 7 at one end providing a working cylinder in which a free piston 8 is operative. The remainingbore portion 9 is also cylindrical and carries a piston 11 therein. Said bore portions and pistons are cooperative to deiine a liquid-receiving space in which a suitable liquid 12, such as a grease or oil, is placed.

For sealing the liquid 12 in the space provlded therefor, cup washers 13 and 14 are preferably disposed against the mutually opposed faces of the pistons 8 and 11 respectively, said washers being shown as free of any attachment to the pistons. Renewal of the liquid in the aforesaid space is arranged to be effected through a duct extending through the body into said space, said duct normally closed by means of a screw plug 15. A spacing ring 16 is mounted within the larger portion of the liquid-receiving space, said ring operative to preventl a crushing of the cup washer 13 between the piston 8 and the shoulder defined at the juncture of the bore portions 7 and 9.

The piston 11 is arranged to be displaced inwardly through the actuation of a plunger rod 17 engaging it, said rod particularly shown as a bolt threadedly engaging a cap 18 which in turn is threadedly mounted on the extreme outer end of the body portion 6. Since a screwing in of the plunger 17 is operative through the piston l1 and liquid charge 12 to effect a displacement of the piston 8, the arrangement is understood to constitute a valveless hydraulic press, the piston 8 being the working piston of the device. rlhe plunger bolt is provided with a head 19 at its protruding end for engagement by a suitable wrench 20, as indicated in Figure 3. It is seen that the described force-multiplying assembly is' provided solely in association with the body portion 6. Externally, the body portion 6 is formedwith hexagonal and knurled portions 21 and 22 to facilitate the assembly and application of the puller unit, as will hereinafter be brought out.

A tubular body portion 23 is provided for iixed and detachable association with the body portion 6. As particularly shown, the body portion 23 is externally threaded at its outer end for engagement in a correspondingly threaded innerend portion of the cylinder bore 7 of the body portion 6 whereby the body portions are arrangedv to be releasably fixed together as a unitary body for the puller unit. It is to be understood, however, that the specific means of fixing the body portions together is generally immaterial to the present invention, since the assembled body structure is utilized as a Lmit.

Externally, and for a major part of the length thereof, the body portion 23 is threaded for engagement in a threaded bore 80 of a tubular member 24 which is provided for xed mounting on an element 25 to be moved along a shaft 26. Between the two threaded portions thereof, as at 27, the body portion 23 is shown as of polygonal outline whereby to facilitate the use of a suitable wrench thereat during the assembly and application of the unit. The bore 28 of the body portion 21 is arranged to freely and slidably receive a thrust rod element 29 for operative extension from the piston 8 and beyond the inner, and free, end of the body portion 23.

As particularly shown in Figure 3, the element 25 comprises a wheel hub which is to be freed of a tapered portion 31 of an axle or spindle comprising the shaft 26, said shaft having a reduced and threaded end portion 32 normally extending from within and beyond the hub end. Externally, the hub extremity is threaded, as for receiving a usual hub cap, and the member 24 is internally threaded at an expanded inner end portion for mounting on said hub extremity.

In the operative application of the described puller unit for removing the hub 25 from the shaft portion which normally carries it, the member 24 is first tightly mounted on the hub threads. Having the piston 8 of the puller unit in an intermediate or outer position thereof in its cylinder, the inner unit end is screwed into lthe bore 30 of the member 24 until the thrust' rod 29 is compressedly engaged between the piston 8 and the opposed end of the shaft 26, this preliminary engagement of the thrust rod being accomplished by manually turning the puller unit. If the engagement of the hub and shaft is not too tight, the application of a wrench to the body at 2l or 27 may be all that is necessary to free the hub; usually, however, it will be necessary to provide a greater force than such turning of the unit will provide, and in such a case the plunger rod 17 would be turned in against the piston 1l for producing a magnified pressure at the piston 8 and so on the rod 29. In the case of the present taper connection, the hub and unit may be manually lifted away as soon as the hub is loosened. It will be understood that the member 24 is in tension during a working application of the puller whereby it constitutes a tension member in contradistinction to the rod or bar 29 which is longitudinally compressed as a thrust member.

It will now be particularly noted that the present engagement of the tension member 24 with the body of the puller is such that the same unit and thrust bar may be used for many different hub and axle assemblies. Furthermore, it is preferred that the thrust bar be of less diameter than the shaft whereby it may extend within the hub, if necessary. The latter situation may occur in an original hub and axle assembly, or would exist if the threaded shaft end 32 should be broken oii`. Since the present thrust bar 29 comprises simply a length of rod of uniform section, replacement thereof with a bar of different length may be readily and inexpensively effected, whereby the present puller is further adapted for its intended use in a wide variety of both usual and unusual working situations.

When the present unit is used in the illustrated manner for releasing an element from a tapered shaft portion which wedgedly engages in a complementary bore of the element, it is seen that the required working movement of the piston 8 is very small. For this reason, it is possible to replace the cup washer 13 with a diaphragm, and such a modified structure is shown in Figure 4 wherein threadedly engaged body portions 41 and 42 are arranged to clamp the perimetric portion of a, diaphragm 43 between them for defining the larger end of the liquid-receiving cavity. As shown, the diaphragm 43 engages a seat 44 defined in the larger bore 45 of the body portion 42, and a bearing ring 46 is engaged between the diaphragm and the opposed end of the body portion 41. In the present instance, the thrust bar 47 is provided with a head 48 for seating against the inner end of the body as a stop whereby to prevent a shearing of the diaphragm 43 at the inner edge of the seat 44.

By further reference to Figure 4, it is noted that a tension member 51 is provided for application to a wheel hub 52 which lacks a threaded end, the member 51 being arranged for bolting to a hub flange portion, and the hub 52 being shown as of a type which mounts a detachable wheel. In the present puller unit, the lengths of the body `portion 41 and thrust bar 47 are both somewhat reduced.

The structural and operative features herein disclosed are also understood to be specifically applicable for moving elements against frictional resistance along shafts of uniform section, mention being made of the mounting and dismounting of bearing sleeves, gears, pulleys, etc. In such a situation, the relatively short stroke of the working piston may be lengthened by lengthening the cylinder lengths in the unit, or the unit may be applied repetitively in the manner taught. Furthermore, if the force required is not too great, the screwing of the threaded body portion into and through a suitable tension member which engages the element to be moved may be used to effect a movement for substantially the full length of such portion. Where the distances of forced movement are relatively great, the length of such body portion could be greater to meet the condition.

From the foregoing description taken in connection with the accompanying drawing, the advantages of the construction and method of operation will be readily understood by those skilled in the art to which the invention appertains, and while I have described the principle of operation, together with devices which I now consider to be preferred embodiments of my invention, I desire to have it understood that the structure shown is merely illustrative, and that such changes may be made, when desired, as fall within the scope of the appended claims.

Having thus described my invention, I claim as new and desire to secure by Letters Patent of the United States the following:

l. In means for forcing an element along a shaft portion which tightly engages in a bore of the element, a tubular body provided with a longitudinal bore therethrough having an enlarged intermediate portion providing a piston-receiving cylinder, a working piston operative in said cylinder, a pressure plunger operative in a smaller portion of said bore, means at said piston and plunger sealing the bore space defined between them, a non-compressible iiuid in said space, means to displace said plunger toward said piston, a free thrust bar slidably engaged solely in the other smaller portion of said body bore, and means tensionally and adjustably connecting said body with said element whereby to permit a compressive engagement of said thrust bar between said piston and the opposed end of said shaft without regard to the position of the piston in the cylinder whereby a minimum movement of said piston through the actuation of said plunger is thereafter necessary for the exertion of a maximum pressure through said thrust bar.

2. In means for forcing an element along a shaft portion which tightly engages in a bore of the element, a tension member provided on the element, a body providing a cylinder and a guideway bore extending axially therefrom, a working piston operative in said cylinder, a free thrust bar intermediately engaged in said guideway bore and operative between the piston and the opposed shaft end, and means connecting the tension member and body for relative adjustment axially thereof whereby said thrust bar may be coactive between the piston and shaft end independently of the position of the piston in the cylinder, said thrust bar of uniform cross-section and arranged for replacement with a bar of like cross-section and different length.

ANDREW M. MclTNTOSI-I. 

